1. Field of the Invention
The Invention is a cheese extruding machine for forming pieces of cheese weighing several ounces or less.
2. Related Art
Petitioner's invention is used to make small pieces of cheese of uniform density and of exact weights and dimensions at high speed, while retaining the skin which is formed on the cheese piece as it is cooled.
The device was designed for forming small pieces of Italian type cheeses such as mozzarella, provolone or scamorza.
In prior art devices, warm plastic cheese is extruded into a stainless mold. A 40 pound block is commonly formed. The mold is chilled, forming a skin on the cheese block which helps hold the shape of the block when the block is ejected from the mold. Such a device is shown in U.S. Pat. No. 4,613,294. The block formed is then put into a brining tank or trough.
After the block has been brined, it can be cut into smaller rectangular pieces by a harp. Such a harp can be seen in U.S. Pat. No. 4,646,602.
Pieces of cheese that have been cut by a harp cannot be bent without cracking. Cutting the block removes the skin formed on the block while cooling.
The skin formed on cheese, during the forming process, has useful properties. A piece of cheese retaining the skin formed can be bent without cracking. It is an object of this invention to make small pieces of cheese retaining the skin formed in cooling.
The density of the cheese in 40 pound blocks and in blocks formed directly out of the screw extruder varies. As the screws slip, cheese consistency varies in the cheese column formed in the extruder.
Brining time required is a function of the size of the cheese block to be brined. A small piece of cheese may be brined in several minutes, while a 40 pound block may require 24 hours of brining. Brining the cheese, chills, salts, hardens and flavors the cheese. It is an object of this invention to make small pieces of cheese and to brine after formation, to lessen brining time.
Small pieces of cheese may be formed by using an extrusion process, as shown in U.S. Pat. No. 4,339,469. In such a process, a screw extruder is used to force a column or rope of cheese out of an extrusion hole, into a brining tank. The ropes, after brining, are then cut to desired sizes.
While the extrusion system retains the useful skin on all but the cut ends, shapes that can be extruded are limited. As the cheese is extruded out of the high pressure extruder into the atmospheric pressure brining tank, the cheese expands unpredictably and takes on irregular shapes. Density of the extruded cheese rope formed by the extruder varies with slippage of the screw extruder. The cheese then must be cut. It is difficult to cut the cheese ropes formed to exact weight.
Petitioner's device forms a surface skin and an internal structure in the cheese piece formed, by working the cheese, that allows the piece to be bent and handled in further processing.
Both the harp and the extruder can be used to produce small individual serving pieces of varying sizes. Because the pieces formed by the harp or extruder vary in size and in density, they must be sold by weight. Size variation also complicates feeding of the individual pieces to other machines.
The invention extrudes warm plastic cheese by means of a screw extruder into a first mold, then while the cheese in the first mold is still plastic, positions the first mold over a second mold and under great pressure, extrudes the cheese in the first mold into the second mold.
The invention is a cheese extruder specifically designed for the production of cheese pieces weighing several ounces or fractions of an ounce.
The extruder comprises a movable mold plate having two adjustable molds mounted on it. The bottom of the molds are open to the entrance of cheese, forced into the mold by a screw extruder, the outlet of which is under and bears on the movable mold plate.
The top of the mold is closed off by a vertically movable mold cap plate.
As the plate moves back and forth over the cheese inlet, the inlet is open to one mold or to the other, or is blocked by the plate. A reciprocating device is shown in the specifications. A rotary mold plate system has been designed.
As one mold is positioned over the cheese inlet, the second mold is positioned over an extrusion mold which has a number of cheese extrusion holes formed in it. The extrusion mold reciprocates in a direction normal to the direction of movement of the mold plate.
The block of cheese formed in the mold carried by the mold plate, is forced out of that mold under pressure into the extrusion mold in which the desired shape and size of the finished piece has been formed. This works the cheese and compresses it.
The extrusion mold is then moved under an ejector plate mounted over a brine trough, and the formed pieces are ejected for brining.